POS1551 DRUG SWITCHING DUE TO INEFFICACY IN PSORIATIC ARTHRITIS PATIENTS TREATED WITH BIOLOGICAL AGENTS. DAILY CLINICAL EXPERIENCE
Authors: M. Rodríguez Laguna, D. Freites Nuñez, M. P. Álvarez, J. P. Otazu Moudelle, C. Martinez Prada, L. León, B. Fernandez, L. Abasolo
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Psoriatic arthritis (PsA) is a chronic and heterogeneous inflammatory disorder that requires targeted treatment. Biological agents are often one of the first therapy regiment; however, PsA patients can experience a first line biological drug lack of efficacy. Although there are currently a variety of therapies, there is a gap of knowledge to identify the correct treatment algorithms that can be followed when PsA patients need to switch their therapy due to inefficacy. <h3>Objectives</h3> To evaluate the switching therapy regimens due to inefficacy in PsA patients on treatment with biological agents. <h3>Methods</h3> Retrospective longitudinal observational study. Subjects: Cohort of patients who assisted the outpatient rheumatology clinic from January 2006 to December 2021, and followed up to June 2022, diagnosed with PsA according to ICD-10 code and on treatment with biological agents. Main outcome: Switching of a first line of biological treatment due to inefficacy. Covariables: Sociodemographic, clinics and treatment. Statistical analysis: To estimate biological agent switching inefficacy rates, survival techniques were used, expressing the incidence rate (IR) per 100 patients*year with their respective CI at 95% [CI 95%]. <h3>Results</h3> 141 patients with a diagnosis of PsA and on treatment with biological agents were included, with an 893.09 Patients*year follow-up. 52.48% were female, the mean age was 48.06 ± 13.22 years and 94 (80.34%) were actively working. 105 patients (74.47%) presented peripheral arthritis and 22 (15.60%) inflammatory low back pain as principal clinical domain. 108 (76.60%) patients had a history of psoriasis at baseline. 262 courses of treatment were recorded. Throughout the follow-up, Tumor necrosis factor inhibitor (TNFi) was the most used biological agent with 192 courses (73.28%) flowed by interleukin-17 inhibitors with 43 (16.41%) courses of treatment. 243 courses were on combination therapy, 185 (76.13) with methotrexate. Describing the switching due to inefficacy, 109 were recorded with a 12.20 IR [10.11-14.72], similar IR occurred according to age range, 79 occurred in female sex (IR 18.28 [14.66-22.79]), 27 (IR 18.12 [12.43-26.42]) presented inflammatory low back pain, 7 (IR 49.54 [23.61-103.91]) had dactylitis and 16 (IR 30.80 [18.87-50.28]) enthesitis. 67 (IR 11.04 [8.67-14.02]) switching had previous history of psoriasis and 65 (IR 10.73 [8.41-13.68]) were on combination therapy with methotrexate. Table 1, shows the therapy regimens switching inefficacy rates for each type of drug. <h3>Conclusion</h3> The biological drug switching rate due to inefficacy in our study was 12.20 per 100 patients*year. In this description study, we have identified some clinical disease manifestations and therapy regimen factors that might affect the drug switching due to inefficacy on PsA. TNFi seems to be the drug with the lowest rate of switching due to inefficacy in our study. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.